The instant invention relates to sail boats and more particularly to a novel adjustable roller furling spar for a sail boat which is adjustable to compensate for irregular stretch in a sail.
The use of roller furling spars, including roller furling masts and booms, is generally known in the sailing field. In this connection, several varieties of roller furling spar constructions have heretofore been available which include longitudinally extending rotatable elements for windingly receiving sails thereon. Many of the heretofore available roller furling spar constructions have been operable for furling sails thereon as well as for reefing sails to maintain them in "partially furled" dispositions. Obviously, devices of this type are used for furling sails in order to prepare them for storage or for when wind and/or sea conditions make it necessary or desirable to operate the respective vessels, to which they are attached, with the sails thereof in fully lowered dispositions. Devices of this type are used for reefing sails under circumstances, such as heavy wind conditions, when it is necessary or desirable to maintain sails in a "partially furled" disposition to reduce the effective areas thereof. Many of the heretofore known devices of this type have been constructed to be operable under sea conditions so that the sail areas of the respective vessels can be adjusted to compensate for changes in wind conditions.
Spar constructions which are generally exemplary of the furling spars hereinabove described and which represent the closest prior art to the instant invention of which the applicant is aware are disclosed in the to Fearon, U.S. Pat. No. 308,146, Tatchell, U.S. Pat. No. 879,986, Tamm, U.S. Pat. No. 2,119,475, Beaudry, U.S. Pat. No. 2,197,654, Wells-Coates, U.S. Pat. No. 2,561,253, and Ingouf, U.S. Pat. No. 4,324,192. However, while these patents teach various types of furling and reefing spar constructions, they do not even remotely teach or suggest the novel furling spar of the instant invention which is adjustable to compensate for irregular stretch in older sails, and hence they are of nothing more than general interest.
A problem heretofore encountered with many sail boats, including sail boats having conventional spar constructions as well as those having furling spars, is the tendency of sails to stretch irregularly as they become older, whereby they become significantly less efficient. In this connection, conventional sails generally comprise a plurality of trapezoidal panels which are sewn together to define a triangular sail configuration. The individual panels themselves frequently stretch irregularly and the areas of interconnection between the panels where they are sewn or stitched together also tend to stretch irregularly. Frequently, the result is that after a sail has been used for two or three years, "baggy" areas appear therein which are caused by irregular stretching. Further, the more a sail is used, the worse this condition becomes, and hence after a sail has been used for several years it can become significantly distorted from its original shape and have several areas which are quite "baggy". These baggy areas not only have disadvantages from an aesthetic standpoint but they also significantly reduce the efficiency of the sail. Heretofore, this problem has not been adequately addressed by the sailing industry and hence the only solution has been to replace older sails when they become distorted or "baggy".
The adjustable roller furling spar of the instant invention, which is operable for both furling and reefing of sails, provides a novel solution to the above mentioned problem of irregular stretch in sails when it is used for the reefing thereof and it also provides solutions to several other problems that have heretofore existed with the known roller furling spar constructions. In this regard, the roller furling spar of the instant invention is adjustable so that it compensates for irregular sail stretch when it is used for reefing, and comprises an elongated, substantially rigid spar base member which is rotatably securable on a sail boat, an adjustable periphery assembly which is attached to the base member and adjustably defines an effective winding cross section of the spar which is adjustable along longitudinally extent thereof, and means for rotating the spar base member and the periphery assembly attached thereto and for adjustably securing them in various rotated dispositions. Upon rotation of the spar, a sail attached thereto is windingly received on the adjustable periphery assembly and since the periphery assembly is adjustable to vary the effective winding cross section thereof along its longitudinal extent, it can be adjusted to compensate for varying degrees of stretch or "bagginess" in various areas of the sail. For example, when an area of "bagginess" appears in a sail, the portion of the spar directly therebeneath can be adjusted to increase the effective winding cross section of the spar in this area so that an additional amount of sail material is wound on the spar in the area of increased cross section to tighten the "baggy" area. In most instances it is only necessary to make such adjustments at the beginning of each boating season since the degree of stretch which normally occurs during a single season is relatively small. After the periphery assembly has been properly adjusted, the spar is operable similar to a conventional furling spar. However, when it is used for reefing a sail, it can maintain even a badly stretched sail in a tight and trim disposition.
The embodiment of the adjustable roller furling spar of the instant invention in spars of various types including masts and booms is contemplated. However, the preferred embodiment of the instant invention comprises an adjustable roller furling boom which also comprises several other features which provide further advantages over the furling spar constructions of the prior art. Specifically, the adjustable roller furling boom of the instant invention preferably further comprises an elongated cowling comprising a pair of elongated substantially rigid shell portions which are mounted on the spar so that they cooperate to define an elongated housing which is slightly outwardly spaced from the adjustable periphery assembly of the spar, the upper edges of the shell portion being in spaced relation to define an elongated longitudinal opening on the upper side of the cowling for receiving a sail on the spar. The shell portions are preferably mounted so that they are resiliently outwardly movable to increase the transverse dimension of the longitudinal opening and so that the lower portions of the shell portions are outwardly pivotable to provide access to the adjustable periphery assembly. The preferred embodiment of the adjustable boom of the instant invention further comprises a rotatable shaft which is securable to a mast so that it extends forwardly therethrough. The spar base member is secured to the aft end of the rotatable shaft so that it is universally pivotable relative thereto, and the rotating assembly for rotating the boom is secured to the rotatable shaft in front of the mast. The rotating assembly preferably comprises a bevel gear mounted on the rotatable shaft and a rotatable worm gear which communicates with the bevel gear to rotate the shaft. Accordingly, the spar is rotatable with the worm and bevel gear assembly and securable in various rotated dispositions therewith. Also in the preferred embodiment, a halyard spool is provided on the rotatable shaft for windingly receiving a halyard attached to a sail thereon as the sail is unwound from the adjustable boom. The halyard spool is preferably dimensioned to receive the halyard thereon at substantially the same rate as the rate at which the sail is unwound from the boom, whereby as the sail is sequentially unwound, it will be raised up the mast a corresponding amount. Another feature of the preferred embodiment of the instant invention is a sail guide which is securable on a mast of the type having a bolt rope tunnel therein. The sail guide comprises a generally triangular plate portion having a bolt rope tunnel along one edge thereof and means which hingedly mounts the plate portion on the lower portion of the mast in spaced relation above the boom. The plate portion is mounted so that the bolt rope tunnel thereof communicates with the bolt rope tunnel of the mast and extends downwardly and generally rearwardly therefrom. Accordingly, the sail guide is operable to guide the fore bolt rope edge of a sail onto a roller furling boom as the boom is rotated and since it is hingedly mounted on the mast, as the sail is wound on the spar, the guide hinges outwardly to properly guide the sail on the spar as the winding diameter thereof is increased by the sail itself as it is wound thereon.
Accordingly, it is a primary object of the instant invention to provide a roller furling spar which can be adjusted to compensate for stretching in older sails when using for reefing.
Another object of the instant invention is to provide an adjustable roller furling boom which includes an adjustable periphery assembly whereby the effective winding cross section of the boom can be adjusted along the longitudinal extent thereof.
Still another object of the instant invention is to provide a furling boom having an outer cowling.
A still further object of the instant invention is to provide a spar assembly which includes a furling boom and a sail guide for guiding the fore end of a sail onto the furling boom.
An even further object of the instant invention is to provide a rotatable furling boom having a halyard spool for windingly receiving a halyard attached to a sail thereon as the sail is unwound from the furling boom.